Device and method for treating skin

ABSTRACT

A device for the cosmetic treatment of skin, especially for epilation, skin remodeling and treatment of acne whereby an appropriate cosmetically effective wavelength of light is produced using a fluorescent material pumped with ultraviolet light from an ultraviolet light source.

This is a Continuation of U.S. patent application Ser. No. 10/319,676,filed Dec. 16, 2002, pending.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to the field of cosmetics, and moreparticularly to methods and a device for performing cosmetic proceduresof the skin including epilation, skin rejuvenation, and the reduction ofacne-related bacteria.

Supplying services in the field of cosmetic treatments is an importantindustry. Such services run the gamut from non-invasive procedures likehair cutting and application of lacquer to finger nails to surgicalprocedures developed for medically necessary reconstructive surgery.

Skin treatments are much sought after cosmetic treatments. A customerseeking a skin treatment typically desires to modify the appearance ofthe skin from a present state to a state that is more “youthful”:smooth, elastic, homogeneously colored and textured. Hairs, creases,wrinkles, scars, shading and texture irregularities are all anathema:the removal or concealing thereof a sought after service.

In the art it is well known that the irradiation of the skin withcertain specific wavelengths of light at relatively high intensities cancontribute to the improvement of the appearance of the skin.

It is known in the art that irradiation with blue light can assist inalleviating the external symptoms of acne. Sebaceous gland found in theskin produce sebum. Ordinarily the sebum migrates out of the hairfollicle along the hair. When a follicle is clogged, the sebum istrapped and becomes a breeding ground for bacteria, especiallypropionbacterium acne. The bacteria as well as the accumulating sebumlead to the appearance of an offensive looking pustule (“pimple”) on theskin that may lead to permanent scarring. One method for treating acneis irradiation of an effected area with blue light having a wavelengthof about 420 nm. When such light is sufficiently intense, endogenicporphyrins are produced. The porphyrins destroy propionbacterium acne,preventing the production of pimples.

It is known in the art that irradiation with red light can assist inepilation. When a hair follicle is heated to a sufficiently hightemperature, the hair follicle is destroyed. Specific red wavelengthshave been found to penetrate to the follicle and heat it to coagulation,yet not burn the skin itself. Details and background of the use of lightfor epilation can be found in U.S. Pat. No. 5,683,380 and U.S. Pat. No.6,280,438 which are incorporated by way of reference as if fully setforth herein.

It is known in the art that irradiation with green light can be used in“skin remodeling”. Green light of sufficient intensity is absorbed bysubcutaneous blood vessels causing damage. The natural healing processesof the damage includes the growth of collagen fibers, giving the skin asmoother and more elastic appearance. Details and background of the useof light for skin remodeling can be found in U.S. Pat. No. 6,387,089which is incorporated by way of reference as if fully set forth herein.

Lasers are a preferred light source in the field of cosmetic skintreatments. Lasers are energetic and monochromatic, allowing efficienttreatment with little collateral damage and few side effects. However,lasers are not versatile and a single device can be used for only aspecific cosmetic treatment. Further, the price of a laser based skintreatment device is prohibitively expensive Lamps, and especially flashlamps, have been used in devices useful for cosmetic skin treatments,see for example, U.S. Pat. No. 4,233,493, U.S. Pat. No. 5,683,380, U.S.Pat. No. 6,280,438 and U.S. Pat. No. 6,387,089. Flash lamps produce abroad wavelength distribution. This allows for great versatility as anycosmetic treatment can be performed: appropriate filters are placed soas to allow only the desired light to reach the skin. However the use offilters is wasteful, as only a small percentage of light energy producedby the lamp is found in any specific wavelength. The amount of energy ofany one wavelength is low so that flash lamp treatments need to berepeated quite often. Further, the fear of exposing the skin to harmfulultraviolet light, abundantly produced by flash lamps, is so high thatlamps and filters are chosen so as not to emit wavelengths of less than500 nm.

In U.S. Pat. No. 6,387,089 a skin remodeling device includes a flashlamp, producing light having 500-2000 nm, fitted with filters preventingthe passage of light more energetic than at least 550 nm.

In U.S. Pat. No. 6,280,438 an epilation device includes a flash lamp,producing light having 500-1300 nm or having 300 nm to 1000 nm, fittedwith filters preventing the passage of ultraviolet light.

In U.S. Pat. No. 5,683,380 taught the use of a xenon flash lamp havingmost energy emitted as light with a wavelength of 200 nm to 1300 nmrange and fitted with filters to remove lower wave lengths.

There is a need for a device that can be used for cosmetic treatmentsthat overcomes the disadvantages of the prior art devices.

SUMMARY OF THE INVENTION

The above and other objectives are achieved by the innovativeillumination device provided by the present invention.

The present invention provides for cosmetic treatment of the skin bypumping a fluorescent material with ultraviolet light and then usingcosmetically useful light produced by fluorescence to perform thecosmetic treatment. Since fluorescence is both an efficient and asubstantially monochromatic process, a large fraction of ultravioletlight produced by a light source is converted to cosmetically usefullight.

Practice of either the device or method of the present invention isbased on providing a light source having an ultraviolet component toilluminate a fluorescent material. By ultraviolet component is meant thepercentage of energy radiated by the light source with a wavelength ofbetween 200 nm and 400 nm of the total energy radiated with a wavelengthof between 200 nm and 1200 nm.

According to the teachings of the present invention there is provided acosmetic skin treatment device comprising a fluorescent material (thefluorescent material pumped by ultraviolet light and emittingcosmetically useful light) and an ultraviolet light source. Byultraviolet light source is meant a self-contained source of lighthaving an ultraviolet component of at least 10%, whether coherent,incoherent, continuous or flashing (pulsed), preferably being a lamp ora laser. Typical such light sources include ultraviolet lasers, Xe flashlamps or Xe—Hg flash lamps.

Clearly the higher the ultraviolet component of the light source thebetter, at least 15% being preferred, more preferred at least 25%, evenmore preferred at least 40% and most preferred more than 50% ultravioletcomponent.

Generally, the light source of the present invention will be containedwithin a non-transparent housing with the fluorescent material acting asa window. The housing prevents any light from reaching the skin exceptwhere desired and directs the desired light (both from the fluorescentmaterial and from the light source) in the desired direction. It isunderstood that the housing can include such features as baffles andlight passages.

Clearly, harmful or otherwise undesired light may pass through the“window” made up of the fluorescent material to the skin. According to afeature of the present invention, cosmetically useful light fromfluorescence is directed at the skin, but ultraviolet light produced bythe light source and not absorbed by the fluorescent material issubstantially prevented from reaching the skin.

According to a feature of the present invention a filter that is nottransparent to ultraviolet light (for example, reflects or absorbs theultraviolet light) is positioned in such a way so that undesired lightfrom the light source is prevented from passing in the cosmeticallyuseful direction (see FIG. 1, below). According to different feature ofthe present invention, the light source is positioned in the housing sothat light from the light source does not travel in the cosmeticallyuseful direction (see, for example, FIGS. 2 and 3).

According to a feature of the present invention, the cosmetically usefullight is substantially red, substantially blue or substantially green.Herein by “substantially red” is meant a wavelength of between 620 nmand 790 nm, by “substantially blue” is meant a wavelength of between 450nm and 495 nm and by “substantially green” is meant a wavelength ofbetween 485 nm and 580 nm.

According to a further feature of the present invention the light sourceis a flash lamp and produces light flashes with a density of between 1and 200 j cm⁻².

There is also provided according to the teachings of the presentinvention method for cosmetic treatment of the skin by a) providing afluorescent material, the fluorescent material pumped by ultravioletlight and emitting cosmetically useful light, b) pumping the fluorescentmaterial with ultraviolet light produced by a light source, and c)directing the cosmetically useful light emitted by the fluorescentmaterial at an area of the skin to be treated cosmetically. Byultraviolet light source is meant a self-contained source of lighthaving an ultraviolet component of at least 10%, whether coherent,incoherent, continuous or flashing (pulsed), preferably being a lamp ora laser. Typical such light sources include ultraviolet lasers, Xe flashlamps or Xe—Hg flash lamps.

According to a feature of the present invention, the area of skin ishirsute and said cosmetically useful light is substantially red.According to a further feature of the present invention, the area ofskin is afflicted with acne and said cosmetically useful light issubstantially blue. According to a still further feature of the presentinvention, the area of skin needs remodeling and said cosmeticallyuseful light is substantially green.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

FIG. 1 is the emission spectrum of a high-pressure xenon lamp;

FIG. 2 is a schematic depiction of a first embodiment of an illuminationdevice of the present invention;

FIG. 3 is a schematic depiction of a second embodiment of anillumination device of the present invention; and

FIG. 4 is a schematic depiction of a third embodiment of an illuminationdevice of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is of an innovative illumination device, whichallows for safe and efficient irradiation of selected areas withselected wavelengths of light. Use of the device of the presentinvention allows performance of, amongst others, three common cosmeticprocedures.

All illumination devices of the present invention are based onconverting the light of commonly available ultraviolet light sources tolight useful in the field of cosmetic treatments using fluorescence.

In FIG. 1 is depicted the emission spectrum of a Quartz-envelopehigh-pressure xenon lamp (such as manufactured by, for example,Perkin-Elmer Optoelectronics (Fremont, Calif., USA) or Xenon corporation(Woburn, Mass., USA)). One skilled in the art recognizes thatcosmetically useful wavelengths make up only a fraction of total energyoutput while the lion's share of radiation is harmful ultraviolet light.Use of such a lamp to treat the skin of a person is clearly undesirable.However, when used in accordance with the present invention, theultraviolet radiation produced by the lamp is efficiently converted tocosmetically useful light.

A first embodiment of an illumination device of the present invention 10is schematically depicted in FIG. 2. Inside a light proof housing 12 isfound a water-cooled quartz-envelope high-pressure xenon flash lamp 14fitted with a reflector. Further in illumination device 10 is foundelectrical pulse-forming network, 15 (such as manufactured byPerkin-Elmer Optoelectronics (Fremont, Calif., USA). Pulse formingnetwork 15 allows flash lamp 14 to produce single or trains of flashes.A typical pulse-forming network can cause a xenon flash lamp, such as14, to generate single or a train of light flashes with a total densityof 1 to 200 j cm⁻² and having a flash width of between 0.5 and 200millseconds in duration.

When activated, flash lamp 14 repetitively produces intense flashes oflight 16 over a wide range of wavelengths, with a large ultravioletcomponent. Ultraviolet pumped fluorescent block 18 absorbs ultravioletlight and re-emits light of a desired wavelength 20. Filter 22 preventsharmful or otherwise undesirable light 16 produced by flash lamp 14 fromexiting the confines of device 10 in the direction of skin 24. As aresult, from device 10 only safe (that is non-ultraviolet) light exitsto illuminate skin 24 for treatment. Further, due to the presence ofultraviolet pumped fluorescent block 18, the intensity of light of thedesired wavelength 20 produced is much higher than prior art non-lasercosmetic illumination devices.

A second embodiment of an illumination device of the present invention26 is schematically depicted in FIG. 3. Inside a light proof housing 28is found a high-pressure xenon lamp 15. When activated, lamp 15 producesintense light 16 over a wide range of wavelengths, with a largeultraviolet component. Ultraviolet pumped fluorescent block 18 absorbsultraviolet light and re-emits light of a desired wavelength 20. Baffles30 which make up part of light proof housing 28 are positioned so thatall light produced by lamp 15 and not confined to light proof housing 28passes through ultraviolet pumped fluorescent block 18 in the directionof non-transparent block 32. Light produced by lamp 15 is thereforeeither used to pump fluorescent block 18 or harmlessly confined withindevice 26. In such a way skin 24 is illuminated only with light ofdesired wavelength 20 produced by ultraviolet pumped fluorescent block18.

A third embodiment of an illumination device 34 of the present inventionis schematically depicted in FIG. 4. Inside casing 36 is found a laser38 that efficiently produces ultraviolet light 40 (such as produced byThermo Laser Science of Mountain View, Calif., USA). A first mirror 42directs ultraviolet light 40 into a glass fiber light guide (SumitaOptical Glass, Inc. Saitama-Urawa, Japan) 44. Glass fiber light guide 44directs ultraviolet light 40 to a second mirror 46. Second mirror 46directs ultraviolet light 40 back through glass fiber light guide 44. Inthe path of ultraviolet light 38 is interposed ultraviolet pumpedfluorescent block 18, held in place by fluorescent block holder 48.Ultraviolet light 40 produced by laser 38 is used to pump fluorescentblock 18 or is harmlessly confined within casing 36 and glass fiberlight guide 44. In such a way skin 24 is illuminated only with light ofdesired wavelength 20 produced by ultraviolet pumped fluorescent block18. It is important to note that casing 36, glass fiber light guide 44,and second mirror 46 are all components making up the housing of device34.

All three devices, 10, 26 and 34, can be configured for a specifictreatment by simply changing the nature of ultraviolet pumpedfluorescent block 18. It is a simple matter to supply a device having aplurality of ultraviolet pumped fluorescent blocks such as 18 that areconfigured so as to be easily replaceable. In FIG. 3, ultraviolet pumpedfluorescent block 18 is depicted as being replaceable, with fluorescentblocks 18 a and 18 b. Fashioning appropriately shaped, fitted anddesigned fluorescent blocks 18, 18 a and 18 b and block holder 46 iswell within the abilities of one skilled in the art after study of thedescription herein. Other variations and possibilities of allowing thereplacement and changing of the fluorescent material in a device of thepresent invention can be designed by one skilled in the art after studyof the description herein.

One skilled in the art will recognize that illumination device 10 andillumination device 26 are most suited for the irradiation and treatmentof large and non-specific skin areas. In contrast, the flexible glassfiber light guide 44 of illumination device 34 allows light to bedirected more accurately to specific skin areas. The choice of whichdevice is preferable depends on operator preference and the treatmentdesired. Since all three devices emit substantially no dangerouswavelengths of light, and since device 26 and device 34 emitsubstantially monochromatic light, little if any harm is caused byimperfect light direction or over exposure to radiation.

In order to perform epilation according to the method of the presentinvention, an ultraviolet pumped fluorescent material that emitssubstantially red light is pumped using a light source rich inultraviolet light. Such material is manufactured and sold under the nameLumilass-R7 by Sumita Optical Glass, Inc. (Saitama-Urawa, Japan),emitting light of substantially 610 nm when pumped by light havingfrequencies of between 250 nm to 420 nm. Lumilass-R7 can emit with abrightness of 10³ lux, sufficient for cosmetic purposes.

In order to perform skin remodeling according to the method of thepresent invention, an ultraviolet pumped fluorescent material that emitssubstantially green light is pumped using a light source rich inultraviolet light. Such material is manufactured and sold under the nameLumilass-G9 by Sumita Optical Glass, Inc. (Saitama-Urawa, Japan),emitting light of substantially 540 nm when pumped by light havingfrequencies between 200 nm and 390 nm. Lumilass-G9 can emit with abrightness of 10⁴ lux, sufficient for cosmetic purposes.

In order to treat acne according to the method of the present invention,an ultraviolet pumped fluorescent material that emits substantially bluelight is pumped using a light source rich in ultraviolet light. Suchmaterial is manufactured and sold under the name Lumilass-B by SumitaOptical Glass, Inc. (Saitama-Urawa, Japan), emitting light ofsubstantially 410 nm when pumped by light having frequencies between 200nm to 400 nm. Lumilass-B can emit with a brightness of 103 lux,sufficient for cosmetic purposes.

The present invention is not limited to the embodiments described hereinbut also relates to all kinds of modifications thereof, insofar as theyare within the scope of the claims.

1. A cosmetic skin treatment device comprising: (a) a fluorescentmaterial, said fluorescent material pumped by ultraviolet light andemitting cosmetically useful, omnidirectional light, said cosmeticallyuseful light primarily of a single color; and (b) a light source, saidlight source producing light having at least an about 10% ultravioletcomponent in a direction so as to illuminate said fluorescent material.2. The device of claim 1 wherein said light source is selected from agroup of light sources consisting of coherent light sources, incoherentlight sources, continuous lamps, flash lamps and lasers.
 3. The deviceof claim 2 wherein said light source is lamp selected from a group oflamps consisting of Xe lamps and Xe—Hg lamps.
 4. The device of claim 1further comprising: (d) a housing configured so as to direct saidcosmetically useful light in a specific direction.
 5. The device ofclaim 4 further comprising: (e) a filter, said filter being nottransparent to ultraviolet light, positioned so as to prevent passage ofultraviolet light in said specific direction.
 6. The device of claim 1wherein said ultraviolet component is at least about 15%.
 7. The deviceof claim 1 wherein said ultraviolet component is at least about 30%. 8.The device of claim 1 wherein said ultraviolet component is at leastabout 40%.
 9. The device of claim 1 wherein said ultraviolet componentis at least about 50%.
 10. The device of claim 1 wherein said singlecolor is red.
 11. The device of claim 1 wherein said single color isblue.
 12. The device of claim 1 wherein said single color is green. 13.The method of claim 1 wherein said light source is a flash lampconfigured to produce flashes of light with a density of between 1 and200 j cm⁻².
 14. A cosmetic skin treatment device comprising: (a) aplurality of blocks of different fluorescent materials, each saidfluorescent material, when pumped by ultraviolet light, emittingcosmetically useful light primarily of a single respective color; (b) aholder for reversibly holding a selected one of said blocks offluorescent material; and (c) a light source for producing light havingat least an about 10% ultraviolet component so as to illuminate saidselected block.
 15. The device of claim 15, comprising a first saidblock that emits primarily red light, a second said block that emitsprimarily green light and a third said block that emits primarily bluelight.